[llvm] r189987 - Added -misched-regpressure option.
Andrew Trick
atrick at apple.com
Wed Sep 4 13:59:59 PDT 2013
Author: atrick
Date: Wed Sep 4 15:59:59 2013
New Revision: 189987
URL: http://llvm.org/viewvc/llvm-project?rev=189987&view=rev
Log:
Added -misched-regpressure option.
Register pressure tracking is half the complexity of the
scheduler. It's useful to be able to turn it off for compile time and
performance comparisons.
Modified:
llvm/trunk/include/llvm/CodeGen/MachineScheduler.h
llvm/trunk/include/llvm/CodeGen/RegisterPressure.h
llvm/trunk/lib/CodeGen/MachineScheduler.cpp
llvm/trunk/lib/CodeGen/RegisterPressure.cpp
Modified: llvm/trunk/include/llvm/CodeGen/MachineScheduler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineScheduler.h?rev=189987&r1=189986&r2=189987&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineScheduler.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineScheduler.h Wed Sep 4 15:59:59 2013
@@ -227,6 +227,7 @@ protected:
PressureDiffs SUPressureDiffs;
/// Register pressure in this region computed by initRegPressure.
+ bool ShouldTrackPressure;
IntervalPressure RegPressure;
RegPressureTracker RPTracker;
@@ -259,8 +260,9 @@ public:
ScheduleDAGMI(MachineSchedContext *C, MachineSchedStrategy *S):
ScheduleDAGInstrs(*C->MF, *C->MLI, *C->MDT, /*IsPostRA=*/false, C->LIS),
AA(C->AA), RegClassInfo(C->RegClassInfo), SchedImpl(S), DFSResult(0),
- Topo(SUnits, &ExitSU), RPTracker(RegPressure), CurrentTop(),
- TopRPTracker(TopPressure), CurrentBottom(), BotRPTracker(BotPressure),
+ Topo(SUnits, &ExitSU), ShouldTrackPressure(false),
+ RPTracker(RegPressure), CurrentTop(), TopRPTracker(TopPressure),
+ CurrentBottom(), BotRPTracker(BotPressure),
NextClusterPred(NULL), NextClusterSucc(NULL) {
#ifndef NDEBUG
NumInstrsScheduled = 0;
Modified: llvm/trunk/include/llvm/CodeGen/RegisterPressure.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/RegisterPressure.h?rev=189987&r1=189986&r2=189987&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/RegisterPressure.h (original)
+++ llvm/trunk/include/llvm/CodeGen/RegisterPressure.h Wed Sep 4 15:59:59 2013
@@ -288,6 +288,8 @@ public:
MF(0), TRI(0), RCI(0), LIS(0), MBB(0), P(rp), RequireIntervals(false),
TrackUntiedDefs(false) {}
+ void reset();
+
void init(const MachineFunction *mf, const RegisterClassInfo *rci,
const LiveIntervals *lis, const MachineBasicBlock *mbb,
MachineBasicBlock::const_iterator pos,
Modified: llvm/trunk/lib/CodeGen/MachineScheduler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineScheduler.cpp?rev=189987&r1=189986&r2=189987&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineScheduler.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineScheduler.cpp Wed Sep 4 15:59:59 2013
@@ -53,6 +53,9 @@ static cl::opt<unsigned> MISchedCutoff("
static bool ViewMISchedDAGs = false;
#endif // NDEBUG
+static cl::opt<bool> EnableRegPressure("misched-regpressure", cl::Hidden,
+ cl::desc("Enable register pressure scheduling."), cl::init(true));
+
static cl::opt<bool> EnableCyclicPath("misched-cyclicpath", cl::Hidden,
cl::desc("Enable cyclic critical path analysis."), cl::init(false));
@@ -477,6 +480,8 @@ void ScheduleDAGMI::enterRegion(MachineB
{
ScheduleDAGInstrs::enterRegion(bb, begin, end, regioninstrs);
+ ShouldTrackPressure = EnableRegPressure;
+
// For convenience remember the end of the liveness region.
LiveRegionEnd =
(RegionEnd == bb->end()) ? RegionEnd : llvm::next(RegionEnd);
@@ -657,6 +662,13 @@ void ScheduleDAGMI::schedule() {
/// Build the DAG and setup three register pressure trackers.
void ScheduleDAGMI::buildDAGWithRegPressure() {
+ if (!ShouldTrackPressure) {
+ RPTracker.reset();
+ RegionCriticalPSets.clear();
+ buildSchedGraph(AA);
+ return;
+ }
+
// Initialize the register pressure tracker used by buildSchedGraph.
RPTracker.init(&MF, RegClassInfo, LIS, BB, LiveRegionEnd,
/*TrackUntiedDefs=*/true);
@@ -820,11 +832,13 @@ void ScheduleDAGMI::initQueues(ArrayRef<
SchedImpl->registerRoots();
// Advance past initial DebugValues.
- assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
CurrentTop = nextIfDebug(RegionBegin, RegionEnd);
- TopRPTracker.setPos(CurrentTop);
-
CurrentBottom = RegionEnd;
+
+ if (ShouldTrackPressure) {
+ assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
+ TopRPTracker.setPos(CurrentTop);
+ }
}
/// Move an instruction and update register pressure.
@@ -841,10 +855,12 @@ void ScheduleDAGMI::scheduleMI(SUnit *SU
TopRPTracker.setPos(MI);
}
- // Update top scheduled pressure.
- TopRPTracker.advance();
- assert(TopRPTracker.getPos() == CurrentTop && "out of sync");
- updateScheduledPressure(TopRPTracker.getPressure().MaxSetPressure);
+ if (ShouldTrackPressure) {
+ // Update top scheduled pressure.
+ TopRPTracker.advance();
+ assert(TopRPTracker.getPos() == CurrentTop && "out of sync");
+ updateScheduledPressure(TopRPTracker.getPressure().MaxSetPressure);
+ }
}
else {
assert(SU->isBottomReady() && "node still has unscheduled dependencies");
@@ -860,12 +876,14 @@ void ScheduleDAGMI::scheduleMI(SUnit *SU
moveInstruction(MI, CurrentBottom);
CurrentBottom = MI;
}
- // Update bottom scheduled pressure.
- SmallVector<unsigned, 8> LiveUses;
- BotRPTracker.recede(&LiveUses);
- assert(BotRPTracker.getPos() == CurrentBottom && "out of sync");
- updatePressureDiffs(LiveUses);
- updateScheduledPressure(BotRPTracker.getPressure().MaxSetPressure);
+ if (ShouldTrackPressure) {
+ // Update bottom scheduled pressure.
+ SmallVector<unsigned, 8> LiveUses;
+ BotRPTracker.recede(&LiveUses);
+ assert(BotRPTracker.getPos() == CurrentBottom && "out of sync");
+ updatePressureDiffs(LiveUses);
+ updateScheduledPressure(BotRPTracker.getPressure().MaxSetPressure);
+ }
}
}
Modified: llvm/trunk/lib/CodeGen/RegisterPressure.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterPressure.cpp?rev=189987&r1=189986&r2=189987&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterPressure.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterPressure.cpp Wed Sep 4 15:59:59 2013
@@ -153,6 +153,24 @@ const LiveInterval *RegPressureTracker::
return LIS->getCachedRegUnit(Reg);
}
+void RegPressureTracker::reset() {
+ MBB = 0;
+ LIS = 0;
+
+ CurrSetPressure.clear();
+ LiveThruPressure.clear();
+ P.MaxSetPressure.clear();
+
+ if (RequireIntervals)
+ static_cast<IntervalPressure&>(P).reset();
+ else
+ static_cast<RegionPressure&>(P).reset();
+
+ LiveRegs.PhysRegs.clear();
+ LiveRegs.VirtRegs.clear();
+ UntiedDefs.clear();
+}
+
/// Setup the RegPressureTracker.
///
/// TODO: Add support for pressure without LiveIntervals.
@@ -163,6 +181,8 @@ void RegPressureTracker::init(const Mach
MachineBasicBlock::const_iterator pos,
bool ShouldTrackUntiedDefs)
{
+ reset();
+
MF = mf;
TRI = MF->getTarget().getRegisterInfo();
RCI = rci;
@@ -177,19 +197,11 @@ void RegPressureTracker::init(const Mach
CurrPos = pos;
CurrSetPressure.assign(TRI->getNumRegPressureSets(), 0);
- LiveThruPressure.clear();
- if (RequireIntervals)
- static_cast<IntervalPressure&>(P).reset();
- else
- static_cast<RegionPressure&>(P).reset();
P.MaxSetPressure = CurrSetPressure;
- LiveRegs.PhysRegs.clear();
LiveRegs.PhysRegs.setUniverse(TRI->getNumRegs());
- LiveRegs.VirtRegs.clear();
LiveRegs.VirtRegs.setUniverse(MRI->getNumVirtRegs());
- UntiedDefs.clear();
if (TrackUntiedDefs)
UntiedDefs.setUniverse(MRI->getNumVirtRegs());
}
More information about the llvm-commits
mailing list